Green streets: Function or frill?

Bill Ryan, Portland Bureau of Environmental Services chief engineer, stands over a bioswale on a footbridge made from leftover pipe from the bureaus Big Pipe project that limited sewage discharges into the Willamette River. February 2014. (Portland Tribune/Jaime Valdez)

Apareceo Lopez levels concrete at a new bioswale under construction along Southeast Division Street in Portland. February 2014. (Portland Tribune/Jaime Valdez)

Some motorists curse the concrete-encased plantings — called bioswales — for gobbling up parking spaces or slowing traffic. Others wonder if they’re another example of improper spending by city utilities at customers’ expense.

A lawsuit by large industrial customers has branded the city’s Gray to Green and other green infrastructure programs as “unauthorized expenditure” and demanded a full accounting of where the money is being spent. Those same companies are bankrolling an initiative on the May 20 ballot to strip the water and sewer bureaus from City Council control, in a bid to reduce utility rates.

In a citywide debate on the proper role of the city water and sewer utilities, it’s a good time to ask: Are these bioswales and related Green Streets projects a good investment for the city’s utility ratepayers? Or are they a nonessential frill pushed by green do-gooders?

“These programs have to be looked at one by one,” to assure they’re primarily serving utility ratepayers, says John DiLorenzo, the attorney who filed the lawsuit by industrial customers. DiLorenzo says there’s been “mission creep” at the city Bureau of Environmental Services, supported by green activists. “They believe this isn’t a sewer agency at all any more,” he says, and instead “is a healthy watershed agency.”

Despite some public skepticism, a growing body of evidence shows that using nature to absorb excess rainwater often is a lot cheaper than funneling it into massive underground pipes. And many cities around the country praise Portland for leading the way from old “gray” pipe-based approaches to new “green” ones.

The city’s Tabor to the River project, which will add some 500 east-side bioswales while replacing century-old sewer pipes starting to fail, is projected to save the city $54 million from a traditional all-gray approach, says Bill Ryan, the Bureau of Environmental Services chief engineer.

“This is the cost-effective solution for the management of stormwater,” Ryan says of the city’s bioswales and related Green Streets projects.

Portland was the early poster child for green street infrastructure around the country. Now that title may be shifting to Philadelphia, which is taking the idea to its grandest scale yet in the United States.

“Early on in our program, it was Portland where we went to see examples of green infrastructure,” says Howard Neukrug, the Philadelphia Water Department commissioner.

Philly — like Portland years ago — has a combined sewer and stormwater collection system that’s often overwhelmed, dumping untreated sewage into nearby rivers. An old-fashioned gray solution would require a 35-foot diameter pipe laid 150 feet below the Delaware River and stretching 30 miles, Neukrug says. “It would take us 100 years to be able to afford it.”

Instead, he pushed an ambitious plan that harnesses nature to absorb the water by spreading green plantings and other projects around the city. A gray approach can do the job, Neukrug says. “But it takes all your wealth of your ratepayers and it buries it in a tunnel underneath the river.”

City initially rebuffed

Portland’s Bureau of Environmental Services, or BES, wanted to rely more on nature to curb its sewage overflows years ago, but the U.S. Environmental Protection Agency balked at relying on what it figured was untried technology, Ryan says. So the city initially designed a traditional approach, relying on massive new underground pipes on both sides of the Willamette to accommodate storm runoff.

The $1.4 billion public works project, later dubbed the Big Pipe, is the single-largest factor that drove up Portlanders’ water and sewer bills — giving momentum to the current campaign to lower rates.

Ironically, rates would be lower now if the city was allowed to use more green instead of gray methods for the Big Pipe, says Mike Houck, director of the Urban Greenspaces Initiative. “At the time, the data was not there,” Houck says.

But the data is there now, in part because of new methods adopted after the Big Pipe project began. The city shelled out $15 million in incentives to Portlanders who disconnected their home gutter downspouts. That diverted rain falling on their rooftops onto their lawns instead of onto the streets, where it often overwhelmed the combined sewer system and sent untreated sewage into the Willamette River.

That one program wound up costing a little more than 1 percent of the total Big Pipe budget, but it diverted 21 percent of the stormwater that was overwhelming the sewer system, Ryan says.

BES also installed a series of sumps or vegetated infiltration facilities that directed stormwater into the ground. That second round of green infrastructure cost $145 million, or 10.6 percent of the total Big Pipe project, but took care of 15.8 percent of the water problem.

By the time the city got around to the biggest part of Big Pipe, a huge tunnel east of the river, it was able to downsize early plans to build an $865 million, 28-foot-diameter pipe. BES cut stormwater discharges enough to build a 22-foot-diameter tunnel costing $625 million.

Once the city factored in operating and maintenance costs of the green infrastructure, BES figured it will still save $65 million to $145 million over time.

When BES turned next to failing sewer pipes that were flooding home basements on the inner east side, it was able to rely more on bioswales, tree plantings and other green features for its Tabor to the River project. BES calculates the new approach adopted in 2006, which replaced 2000 plans that had not yet been carried out, shaved construction costs from $144.1 million to $80.5 million.

How it saves money

It’s not that pipes aren’t needed any more for sewers and stormwater. However, experts say if done right, a mix of gray and green elements can save money. Dumping less stormwater into the sewers sometimes means cities may not have to dig up streets to put in bigger pipes, or they can build smaller pipes. They also can downsize pumping systems needed to move massive amounts of water and sewage, saving money on construction, maintenance and energy. And there’s less material sent to the sewage treatment plant.

Experts caution that green infrastructure often is cost-effective when done in tandem with other projects, such as sewer replacements that require a street to be dug up.

“Any time you build something just for the sake of building green infrastructure, it’s going to be very costly,” Neukrug says.

The EPA changed its tune and now advocates green stormwater programs such as those pioneered in Portland. A 2007 EPA study found that 11 of 12 green infrastructure projects saved money when compared to doing the same project with pipes and other gray technology.

The American Society of Landscape Architects did a more comprehensive survey of 479 case studies in 43 different states. It found that green infrastructure reduced overall costs in 44.1 percent of the cases, cost the same in 31.4 percent of the cases, and cost more 24.5 percent of the time.

“If they’re revenue-neutral, that’s great,” Houck says, “because you get a huge number of other benefits.”

Portland State University students also showed that bioswales filter out lead and other heavy metals in the water flowing along streets, keeping it from getting into the Willamette River, where it may harm fish and other species.

Students led by by PSU environmental science professor Alan Yeakley simulated storm conditions and analyzed the water draining into several bioswales and the material emerging from them before it went into the sewer and stormwater system.

“We found an 80 percent reduction of those metals coming in and going out,” Yeakley says. “It helps not just the water. It helps recover our streams.”

Kent Craford, co-petitioner on the initiative to create an independently run city water and sewer utility district, says he and his backers don’t necessarily oppose the Green Streets initiatives. The lawsuit is more concerned with abuses of city water and sewer funds, for example, used to acquire park land or promote bike paths, he says.

If the “primary purpose” of those improvements is to benefit ratepayers, “then it’s probably a legitimate expense,” he says.

“If it saves as much money as they say it has, then great,” Craford adds. “If they have ancillary benefits like beautifying the street, and using natural processes that rely less on more intervention in the landscape, then great.”

Ryan says BES only pursues green infrastructure projects when it saves overall costs. The environmental benefits aren’t factored into the cost-benefit analysis the agency uses, he says, though they surely bring added value.

“Does it make for a better community? Yes,” says Dean Marriott, BES director. “What we count is the economic difference.”

Though Craford is trying to draw a distinction between cost-effective city utility services and those he and other critics deem improper use of utility funds, it’s unclear if voters will make such a clear distinction. And if voters pass the May initiative, there’s no guarantee what policies the newly elected water district board will pursue.

Houck says the lawsuit and ballot measure campaign are part of a “broad brush attack on all of the green programs.”

“It’s throw enough mud around and hope some of it sticks,” Marriott says, referring to the lawsuit. “That’s what they’re doing.”